What Kind Of Gas Does A Lawn Mower Use And How Much Gas I Need?

Every homeowner has a lawnmower in their garage, and next to it, you’ll find a gas can. You may think that a lawnmower uses the same gas as your car, but in many cases, that’s not correct.

If you use the wrong type of fuel, you could irrevocably damage your mower’s engine as well. With some mower brands, using fuel not specific in your owner’s manual also voids your warranty. As you can see, you must know what type of fuel goes into your mower.

However, which brand of gas will help your lawn mower run the best? We provide the answer and other tips for maintaining your lawnmower, such as when to add oil.

Learn How to Gas Up Your Lawn Mower

You’ll need to know the type of lawnmower by the engine. Your owner’s manual should provide you with the exact type of engine and even the best fuel.

There are typically two types of lawnmower engines: four-stroke and two-stroke engines. However, most lawn mowers today have four-stroke engines. Larger engines will have 140-cc to 190-cc. These are made for taller, more robust grass as well as leaf mulching (for instance, you can find best lawnmowers for 1 acre here).

Types of Gas for Lawn Mowers

Once you know the type of engine in your lawnmower, you can quickly determine the type of gas necessary to keep your machine working.

Four-Stroke Engines

If you have a four-stroke lawnmower, you will have fresh, clean, unleaded gasoline with an octane rating of 87 or higher.

Two-Stroke Engines

The recommendation to use the same type of gas with a two-stroke engine, but you may also add two-cycle engine oil.

Varies by Brand

We suggest not going by this guide alone, as you’ll want to check the owner’s manual and understand the differences between brands. For example, Briggs & Stratton has two-stroke lawnmowers. You’d use 50 parts of gas to 1 part oil for these motors.

Add Fuel Stabilizer

Perhaps you don’t plan to mow your lawn for some time. In these cases, you probably will store your lawnmower away.

To keep your fuel intact, you may want to add a fuel stabilizer agent with a full tank of gas. This prevents the gas from evaporating.

How Much Gas to Put in a Lawn Mower

Do you have a push lawn mower or a riding mower? The answer much depends on the make and model of your lawnmower. For any lawnmower, you should be able to consult the owner’s manual on the specific liters for your gas tank.

1. Walk-behind mowers typically only need a half liter at the most. However, the capacity of the tank may be more.
2. However, a medium-sized riding mower typically holds about two gallons.
3. Larger tractors and riding mowers may have gas tanks that accept three to four gallons.

Experts say that you shouldn’t use any gas with more than 10% ethanol, or you may damage the engine after one or two fill-ups.

How to Fill Your Gas Lawn Mower

When purchasing a lawnmower, you should always check that the gas tank and oil chamber are easy to find, as you’ll be maintaining these fuels throughout the lifetime of your mower.

Step 1: Locate the Gas Tank

Most walk-behind lawnmowers have a small plastic tank on the side of the mower or at the back. In riding mowers, it’s typically located on one side towards the back, just like a car.

Other mowers have a covered gas tank that’s hidden. You may have to find it underneath a cap or symbol.

Step 2: Remove Gas Cap

Just like a car, you’ll typically need to remove a cap by twisting it counterclockwise. There may also be caps that lock in place or others that require a key.

Step 3: Fill Up Your Tank

Determine what gas is best for your engine. If it’s fresh, unleashed gasoline, you can get the same fuel at a gas station.

Step 4: Tighten the Gas Cap and Go!

Once your done filling the tank, you can place the gas cap back on and tighten it. Your lawn mower should be good to go.

Mistakes to Avoid When Filling Up Lawn Mower

Lawnmowers can be finicky machines. This is because they are typically left in storage for many months when it gets colder or used too frequently to cut moist grass. If not cleaned properly, your lawnmower may stop firing up at all.

However, there also cases when fuel damages your lawnmower. For example, if you drain your lawn mower’s tank before storing it in the winter, you’ll likely have a hard time starting it back up.

• Draining the tank harms your lawn mower’s carburetor
• Small droplets of gas are left behind and typically start to get sticky, like a varnish
• If gas gets stuck in the needle valve tip, the carburetor will be damaged and won’t work properly
• Gas tanks shouldn’t sit empty for long periods as water vapor can get in the tank and start to condense, triggering rust and corrosion
• Use a gas stabilizer agent instead when storing your lawnmower

To use a gas stabilizer, you’ll fill your tank almost entirely with fresh, clean unleaded gasoline. Then add a fuel stabilizer. You can use this with old fuel, but it’s best to use it when it is fresh.

Turn on your lawnmower and let the engine run for a few minutes to get the stabilizer running through your fuel lines and carburetor. Your lawn mower should be ready for storage now.

Do You Put Same Gas as Cars in Lawn Mowers?

Typically, yes, the gas is the same for your lawnmower as it is for your car. However, you should always search your mower in Google with the model number and check what gas is best for your model.

Older models of lawnmowers typically do not handle any gas with ethanol well.

Unleaded gasoline today contains as much as 10% ethanol, so you’ll need to check the model before merely filling up at your local gas station.

Do You Add Oil Separately in Lawn Mower?

When it comes to maintaining your lawnmower, you’ll need to check and replace the oil from time to time.

You should change the oil for all new mowers after the first five hours of use; then, you’ll change it before a new mowing season in spring or summer. This also equates to about 50 hours of use.

Most lawn mowers have a separate oil chamber with an oil plug. You’ll need to check the oil filter to see if it’s filled with oil debris. If so, this should be replaced as well.

Lawn Mower Filters

Did you know that your lawnmower may also have oil and air filters? Depending on your model, you may have multiple filters that need to be checked periodically.

It’s best to replace an oil filter once a year or before heavy-duty lawn mowing in early spring and summer.

Doyle Mathews Lawn Expert

Pro Tip: Mower air filters should also be replaced every three months if consistently mowing each week. For many, you are replacing your air filter once per year before summer is enough. There are also two filter types for specific mower models, including the primary filter and a foam filter.

Most mowers have paper air filters that prevent any large particles from getting into the combustion chamber. You can find these filters located beneath the cover of your lawnmower, but it’s best to check your manual specifications.

FAQ

Conclusion

Using the right type of gas in your lawnmower is essential to maintaining a long life-span. Most riding mowers use the same type of gas that you use in your car, but one rule is never to use high ethanol.

In addition to gas tanks, you should also monitor your mower’s oil and make sure that you are changing your filters for optimal performance.